Railroad vehicle control system

ABSTRACT

A railroad vehicle control system governed by a wayside computer has a communications channel for each track section in the territory for periodically exchanging information between said computer and said railroad vehicle wherein the improvement comprises a tachometer means governed by the rate of rotation of the wheels of said vehicle for producing pulses indicative of the actual speed in accordance with said rate of rotation. The computer includes a control stage for calculating speed, and generating desired speed control signal pulses for transmission to the vehicle and a checking stage responsive to said control stage for validating the desired speed signal. A standby stage responsive to the control and checking stages assumes control and checking functions upon failure of either of said stages. A comparator responsive to the control and actual speed pulses increases and decreases the speed of the vehicle until the frequency of the actual speed pulses equals the frequency of desired speed pulses.

llnite Smith RAILROAD VEHICLE CONTROL SYSTEM [75] Inventor: Willis R.Smith, Rochester, NY.

[73] Assignee: General Signal Corporation,

Rochester, NY.

[22] Filed: Oct. 15, 1971 [21] Appl. No.: 189,731

Related US. Application Data [63] Continuation of Ser. No. 14,909, Feb.27, 1970.

[52] U.S. Cl. ..246/63 C, 179/82, 246/182 C [51] Int. Cl. ..B6ll 3/18[58] Field of Search ..246/187 B, 63 C, 246/63 R, 4, 3, 2, 182 C, 182 R;235/153 AE; 340/1461 BE, 152 T; 179/82 [56] References Cited I UNITEDSTATES PATENTS 3,268,727 8/1966 Shepard ..246/187 B 3,045,112 7/1962Hailes ..246/l87 B 3,348,197 10/1967 Akers, Jr. et al.. ..235/l53 AE3,676,669 7/1972 .lauquet ..246/63 C 1 MILE COMMON STORE May 1, 1973[57] ABSTRACT A railroad vehicle control system governed by a waysidecomputer has a communications channel for each track section in theterritory for periodically exchanging information between said computerand said railroad vehicle wherein the improvement comprises a tachometermeans governed by the rate of rotation of the wheels of said vehicle forproducing pulses indicative of the actual speed in accordance with saidrate of rotation. The computer includes a control stage for calculatingspeed, and generating desired speed control signal pulses fortransmission to the vehicle and a checking stage responsive to saidcontrol stage for validating the desired speed signal. A standby stageresponsive to the control and checking stages assumes control andchecking functions upon failure of either of said stages. A comparatorresponsive to the control and actual speed pulses increases anddecreases the speed of the vehicle until the frequency of the actualspeed pulses equals the frequency of desired speed pulses.

7 Claims, 3 Drawing Figures CONTROL CHECKING C STAND BY CONTROL ANDCHECKING Patented May 1, 1973 2 Sheets-Sheet 1 QZ SIQ E2 401F200mmPDaEOO 2 Sheets-Sheet 2 mm OmkzOo m GI RAILROAD VEHICLE CONTROL SYSTEMThis is a continuation, of application Ser. No. 14,909 filed 2/27/70.

BACKGROUND OF INVENTION This invention relates to railroad vehicle speedcontrol systems and more particularly to a control system for a railroadvehicle governed by a computer over a specified length of trackterritory.

In railroad vehicle control systems a specially designed limited purposecomputer may be incorporated for controlling the track territory underconsideration. The functions of these computers are often times limitedto the specific requirements of the particular installation and as suchdo not provide a great deal of flexibility for expansion of the systemfor auxiliary controls. As a matter of fact, the computer controllingthe vehicles over track circuits and the like may not have additionalapparatus for checking or standby because of the complexity and expenserequired by such duplication. A failure of the main computer willnecessarily result in a track territory without signals which isobviously a hazardous situation. Besides the danger involved in aninoperative signaling system, the traffic using that territory isnecessary delayed until the computer is brought back into operation orpossibly slower acting manual controls are used to communicate with thevehicles in the section.

Track circuits have also presented certain problems in these signalingsystems in that a failure of an insulated joint or high frequency bypassapparatus which separates one track section from another would alsointerfere with the efficient operation of the signaling system.

In addition to these problems, auxiliary controls such as highwaywarning crossing devices and switches require separate track circuitsfor their actuation and field located apparatus for determining the timefor energizing these devices. Many of these systems have their ownspecial purpose apparatus for controlling the warning signals and assuch as rather independent of the surrounding systems. This independencewhich these auxiliary systems possess often adds nothing in the way ofsafety to the system and also provides for unnecessary duplication offunction along the territory.

It is therefore an object of the present invention to provide anarrangement which substantially obviates one or more of the limiationsand disadvantages of the described prior arrangements.

It is another object of the present invention to provide a computercontrolled railroad vehicle control system having checking and standbyfunctions for eliminating delays and danger provided by a signalfailure.

It is another object of the present invention to provide a system whichwill actuate auxiliary devices from a central location.

It is still another object of the present invention to provide a controlsystem wherein train carried apparatus responding to computer signalsfrom the central location controls the vehicle in accordance with saidcomputer signals.

It is another object of the present invention to provide a system forcommunicating to and from a railroad vehicle without the use of trackcircuits.

SUMMARY or INVENTION There has been provided a railroad vehicle controlsystem governed by a wayside computer. This system has a channel foreach track section in the territory for periodically exchanginginformation between said computer and the railroad vehicle and theimprovement comprises tachometer means governed by the rate of rotationof the wheels of said vehicle for producing pulses indicative of theactual speed in accordance with said rate of rotation. The computerincludes a control stage for calculating the desired speed andgenerating the desired speed and acceleration control signal pulses fortransmission to the vehicle, a checking stage responsive to said controlstage for validating a desired speed signal, and a standby stageresponsive to the control and checking stage for assuming control andchecking functions upon failure of either of said stages. Comparatormeans carried on the vehicle responsive to the control and actual speedpulses increases and decreases speed of the vehicle until a frequencysignal of the actual speed pulses equals the frequency of the desiredspeed pulses.

For a better understanding of the present invention together with otherand further objects thereof, reference is had to the followingdescription taken in connection with the accompanying drawings while itsscope will be pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a drawing in block formillustrating the computer control and communications channel to therailroad vehicle.

FIG. 2 is a drawing showing the train carried apparatus for controllingthe speed of the vehicle in accordance with the computer signals.

FIG. 2A is a device for providing redundancy and train lengthinformation to the computer.

DESCRIPTION OF THE PREFERRED EMBODIMENT Theconfiguration of the presentinvention contemplates the use of a computer for automaticallycontrolling signaling systems, switching and speed control along apredetermined section of railroad right of way. A main computer Agoverned by a master program generates output signals for the control ofthe wayside apparatus such as switch 20, train length detector 22, andspeed control communication loops 30A, B and C. The computerinput-output [/0 is coupled to these various devices over dedicatedtransmission lines to each of the devices. This has been chosen in orderto provide safety to the system. It is also apparent that the use ofdedicated lines obviates the necessity for complex coding and decodingapparatus which would be required if a single communications line wereused with several inputs from the various devices. The computer U0 isparallel in configuration and therefore each wayside device isidentified by its particular input to the computer A.

In order to control the speed of a railroad vehicle in control loop 30A,an output signal from control computer A is transmitted over line 3A toprimary transmitting coil 31A. This is inductively coupled with loopcoil 30A through transformer coil 33A. The signal from computer A overline 3A is a frequency shift carrier signal having three states; high,low or center frequency which correspond to and off respectively.

In FIG. 2 the carrier frequency transmitted from control computer A isreceived inductively from loop 30A by receiving loop 40A. This signal iscoupled to direction control 41 which includes filters 42 and 43. Thesefilters detect whether the frequency shift from the carrier frequency ispositive or negative; and according to the present invention, filter 43detects a positive shift indicating a forward direction and filter 42detects negative-going pulses indicating a reverse desired speed.Forward being in the direction from left to right in the drawing. Thespeed pulses are transmitted through OR gate 45 and command speed gate46 to comparator 47 for transmission to vehicle propulsion and brakingcontroller 48.

The vehicle contains an electromechanical tachometer for generatingsignals of actual speed for comparison in comparator 47. This tachometerincludes an axle generator 49 having teeth thereon 50 and magnetic pickup 51 for detecting the passage of the axle teeth. Pulses generated bythe interaction of the teeth 50 and magnetic pick up 51 are transmittedto the actual speed gate 52 and thence to the comparator 47. If thesignals from demand speed gate 46 exceed actual speed pulses, thencomparator 47 generates a signal indicating an increase in speed. Therate of increase or decrease of the demand speed pulse provides anacceleration or deceleration proper for attaining the desired speed.However, if the actual speed pulses lead the demand speed pulses thenthe comparator generates a signal for slowing down the vehicle fortransmission to vehicle propulsion and braking controller 48. Thesignals from magnetic pick up 51 are also coupled to direction logic 53which is similar in nature to the direction control 41 in that ittransmits a directional output to flip-flop 55 which is coupled totransmitting loop 56. This transmitting loop generates a signalcorresponding to the actual speed of the vehicle and this ismagnetically coupled to loop 30A and transmitted back to the computerover coil 33A and secondary receiving coil 32A, thence to wire 4A to thecomputer A.

The information received by computer A and other vital data required inthe automatic control of railroad vehicles is stored in common storagearea D. This common storage area has inputs and outputs to computers A,B and C and is capable of supplying information necessary for specificfunctions of these computers upon demand. The of computer A is directlycou-' pled to the I/Os of computer B and C. Information received bycomputer A is analyzed by computer B and the resulting signals generatedby computer A are received and compared by computer B with the availableinformation for checking the operability of com puter A. Computer C isused for a standby control and checking computer. It is capable ofgenerating control signals and checking the operability of computer A.If the signals generated by the control computer A are not in agreementwith the results derived by checking computer B, it is apparent that oneof the two computers A or B is malfunctioning. Under thesecircumstances, standby computer C is activated and if the results ofcomputer A and C are in agreement, computer B is deactivated and standbycomputer C assumes the function formerly handled by computer B. In theevent that the standby computer agrees with the results of computer B,then A is deactivated and computer C controls the operation of therailroad section under consideration. The leads CK and CC coupled fromcomputer C to computer B and A respectively are energized for inhibitsignals to those computers when C assumes control of the particularfunction.

Control of track sections 30C and 30B are similarly coupled over lines1B, 2B, 3B, 4B and 1C, 2C respectively. The computer A havinginformation concerning each block in the system can maintain headwaysand control the speed of the train very accurately because it is inconstant communication with each of the sections in the right of way andhas information relative to the various functions of the vehicles withinthe track section. When, for example, a vehicle is travelling from leftto right in the drawing in block 30C, the position of the train as itenters the block 30C is detected by the extreme coil 33C. Vehicleoccupancy is then transmitted over secondary receiver 31C and wire 3C tocomputer A. In addition, the transmitting loop 56 generates a signalcorresponding to the actual speed of the vehicle. If necessary, a signalfrom computer A over line 1C to primary transformer coil 32C isgenerated for adjusting the desired speed of the vehicle. However,assuming no change in speed is necessary, the speed of the vehicle isknown and the time necessary for the vehicle to reach the highwaycrossing HC is determined because it is assumed that the computerprogram has this fixed data stored in common storage D. Knowing thespeed of the vehicle and its position, the highway crossing warning 57may be actuated in a uniform time before the vehicle reaches thecrossing. This is accomplished by transmitting a signal for computer Aover wire 5 to transformer 58 for deenergizing relay 59. Thedeenergization of a relay for activating a highway crossing signal isknown in the art as a conventional way of providing fail-safe operationto highway crossing apparatus.

The actuation of switch 20 may be accomplished through relays 60 and 61by activation of normal and reverse transformers 62 and 63 respectively.These are in turn activated over lines 11 and 7 respectively fromcomputer A. Since the position of the vehicle and its speed arecalculated from inputs from loop C, switch 20 may be actuated to aposition as required by the particular situation. Contactors 55 and 56of relays 60 and 61 respectively are actuated in accordance with signalstransmitted to the relays over transformers 62 and 63 and provide asignal to the computer over wires 9 and 8 respectively that the desiredrelay has been activated. Contactor 65 checks in this embodiment theactivation of the switch 20 to the normal position which is essentialfor safe main line train operation. The contactor 65 is controlled byapparatus at the switch which detects the position of the railroadswitch points in switch 20. If a normal position is called for, then andit is not detected; that is, if contactor 65 is not closed to theforward position, then signals transmitted to wayside equipment forstopping the train are put in effect. The only way a train may move isin response to signals from the wayside and an absence of the signalswould, by virtue of the logic, require a stop.

Train length may be accomplished by a number of methods of thisembodiment. The FIG. 2A shows a second tachometer system which consistsof an axle 49', 50' and magnetic pick up 51'. The teeth 51' activate themagnetic pick up and as it rotates produces pulses to activate flip-flop55' to which is coupled rear end transmitting loop 56'. As the trainenters, for example, block A from the left, the front end transmittingloop 56 provides an indication of vehicle presence to computer A. Thecomputer also receives information as to the speed of the vehicle fromthe inputs as previously described and when the rear end of the trainenters the block A, another signal is transmitted over transmitting loop56'. This gives indication of the vehicle length in terms of the timeelapsed since the entry of loop 56 in block A, and the speed of thevehicle. In addition, this second tachometer of FIG. 2A also providesredundance of speed information to the computer for checking theaccuracy of the system. A second train length detector has beenincorporated in the case where a tachometer is shown in FIG. 2A is notpresent at the rear of the train. The sensors 67 and 68 may bephoto-cells or other detector equipment known in the art which providesignals to the input of computer A for determining the length of thetrain.

If computer A is incapableof handling more than a certain number ofinputs at one time interval, the wayside blocks 30A, B and C may berepeated along the right of way, and a scan of various sections of theright of way may be accomplished. However, it is contemplated that allthe necessary information for controlling the right of way over adistance of perhaps 100 miles or more may be handled by a signal controlcomputer A, and the checking and standby computers B and C respectively.

There has therefore been provided a railroad vehicle control systemgoverned by a wayside computer obviating the limitations previouslydiscussed and providing self-checking, elimination of track circuits andtrack bondings and accurate speed control.

The system also provides for an extremely high amount of flexibility inthat it can control a number of wayside signaling devices such asswitches and warning signals without the necessity of complicatedwayside apparatus.

The system described provides safety to each aspect of the functionsprovided because it is a dynamic system. There is continuous exchange ofinformation between the computer and the various wayside devices and theabsence of signal indicates a dangerous condition.

While there has been described what at present is considered to be thepreferred embodiment of the present invention, it will be obvious tothose skilled in the art that various changes and modifications may bemade therein without departing from the invention and it is thereforeaimed in the appending claims, to cover all such changes andmodifications that fall within the true spirit and scope of theinvention.

What is claimed is:

l. A railroad vehicle control system governed by a wayside computerhaving an input-output channel for each track section in the territoryfor continuously exchanging information between the computer and a trainincluding at least one railroad vehicle wherein the improvementcomprises:

a. a plurality of closed loop circuits laid end-to-end along a track,each of said closed loop circuits having a receiving coil at one end ofa track section and a transmitting coil at the other end of the tracksection for exchanging signals between a railway vehicle within thesection and the wayside computer;

. a pulse receiving means for receiving signals transmitting from thewayside computer through the transmitting coil of one of said closedloop circuits to the railroad vehicle and extracting from such signals aplurality of pulses, the frequency of such pulses indicative of adesired railroad vehicle speed calculated by the wayside computer;

c. a tachometer means governed by the rate of rotation of the wheels ofsaid vehicle for producing a plurality of pulses, the frequency of suchpulses indicative of actual speed of the railroad vehicle; and

. a comparator means responsive to the plurality of pulses indicative tothe desired vehicle speed and responsive to the plurality of pulsesindicative of the actual speed of the railroad vehicle for increasingand decreasing the speed of the vehicle until the frequency of theactual speed pulses equals the frequency of the desired speed pulses.

2. The control system of claim 1 wherein the pulses indicative of theactual speed of the railroad vehicle are transferred through thereceiving coil of one of the closed loop circuits to the waysidecomputer for providing to the wayside computer feedback indications ofthe railroad vehicles response to the desired speed signals from thewayside computer.

3. The control system of claim 2 wherein the transmitting coil fortransferring signals to the railroad vehicle from the computer and thereceiver coil for transferring signals to the computer from the railroadvehicles are in the same track section as the railroad vehicle and partof the same closed loop circuit.

4. The control system of claim 3 wherein said tachometer means includesa first tachometer means operative on a first railroad vehicle at thefront end of the train and a second tachometer means operative on a lastrailroad vehicle at the rear end of the train for providing signals fromsaid first and second tachometer means to the computer when the firstvehicle and the last vehicle enter each track section.

5. A railroad vehicle control system for automatically controlling themonitoring the travel of a railroad vehicle along a plurality of tracksections, wherein the improvement comprises:

a. wayside computing means having an input-output channel for each tracksection for continuously exchanging information between said computermeans and the railroad vehicle;

b. a plurality of closed loop circuits laid end-to-end along a track,each of said closed loop circuits having a receiving coil at one end ofa track section and a transmitting coil at the other end of the tracksection for exchanging signals between a railway vehicle within thesection and said wayside computing means;

c. pulse receiving means for receiving signals transmitted from saidwayside computing means through the transmitting coil of one of saidclosed loop circuits to the railroad vehicle and extracting from suchsignals a plurality of pulses, the frequency of such pulses indicativeof a desired railroad vehicle speed calculated by said wayside computingmeans;

. tachometer means governed by the rate of rotation of the wheels ofsaid vehicle for producing a plurality of pulses, the frequency of suchpulses indicative of actual speed of the railroad vehicle; and

e. comparator means responsive to the plurality of pulses indicative ofthe desired vehicle speed and responsive to the plurality of pulsesindicative of the actual speed of the railroad vehicle for increasingand decreasing the speed of the vehicle until the frequency of theactual speed pulses equals the frequency of the desired speed pulses.

6. The control system of claim wherein said wayside computing meansincludes a first, second, and third computing means having common inputsand outputs, said first computing means calculating the desired railroadvehicle speed and outputting corresponding desired speed control signalsfor transfer to the railroad vehicle, said second computing meansresponsive to said first computing means to validate and to invalidatethe outputted desired speed control signals, and said third computingmeans responsive to said second computer means for assuming thecalculating and outputting functions of said first computing means whensaid second computer means invalidates the outputted desired speedcontrol signals from the first computing means.

7. The control system of claim 6 wherein said wayside computing meansinclude a data storage area having inputs and outputs to each of saidfirst, second and third computing means for providing data storagecommon to each of said computing means.

1. A railroad vehicle control system governed by a wayside computerhaving an input-output channel for each track section in the territoryfor continuously exchanging information between the computer and a trainincluding at least one railroad vehicle wherein the improvementcomprises: a. a plurality of closed loop circuits laid end-to-end alonga track, each of said closed loop circuits having a receiving coil atone end of a track section and a transmitting coil at the other end ofthe track section for exchanging signals between a railway vehiclewithin the section and the wayside computer; b. a pulse receiving meansfor receiving signals transmitting from the wayside computer through thetransmitting coil of one of said closed loop circuits to the railroadvehicle and extracting from such signals a plurality of pulses, thefrequency of such pulses indicative of a desired railroad vehicle speedcalculated by the wayside computer; c. a tachometer means governed bythe rate of rotation of the wheels of said vehicle for producing aplurality of pulses, the frequency of such pulses indicative of actualspeed of the railroad vehicle; and d. a comparator means responsive tothe plurality of pulses indicative to the desired vehicle speed andresponsive to the plurality of pulses indicative of the actual speed ofthe railroad vehicle for increasing and decreasing the speed of thevehicle until the frequency of the actual speed pulses equals thefrequency of the desired speed pulses.
 2. The control system of claim 1wherein the pulses indicative of the actual speed of the railroadvehicle are transferred through the receiving coil of one of the closedloop circuits to the wayside computer for providing to the waysidecomputer feedback indications of the railroad vehicle''s response to thedesired speed signals from the wayside computer.
 3. The control systemof claim 2 wherein the transmitting coil for transferring signals to therailroad vehicle from the computer and the receiver coil fortransferring signals to the computer from the railroad vehicles are inthe same track secTion as the railroad vehicle and part of the sameclosed loop circuit.
 4. The control system of claim 1 wherein saidtachometer means includes a first tachometer means operative on a firstrailroad vehicle at the front end of the train and a second tachometermeans operative on a last railroad vehicle at the rear end of the trainfor providing signals from said first and second tachometer means to thecomputer when the first vehicle and the last vehicle enter each tracksection.
 5. A railroad vehicle control system for automaticallycontrolling the monitoring the travel of a railroad vehicle along aplurality of track sections, wherein the improvement comprises: a.wayside computing means having an input-output channel for each tracksection for continuously exchanging information between said computermeans and the railroad vehicle; b. a plurality of closed loop circuitslaid end-to-end along a track, each of said closed loop circuits havinga receiving coil at one end of a track section and a transmitting coilat the other end of the track section for exchanging signals between arailway vehicle within the section and said wayside computing means; c.pulse receiving means for receiving signals transmitted from saidwayside computing means through the transmitting coil of one of saidclosed loop circuits to the railroad vehicle and extracting from suchsignals a plurality of pulses, the frequency of such pulses indicativeof a desired railroad vehicle speed calculated by said wayside computingmeans; d. tachometer means governed by the rate of rotation of thewheels of said vehicle for producing a plurality of pulses, thefrequency of such pulses indicative of actual speed of the railroadvehicle; and e. comparator means responsive to the plurality of pulsesindicative of the desired vehicle speed and responsive to the pluralityof pulses indicative of the actual speed of the railroad vehicle forincreasing and decreasing the speed of the vehicle until the frequencyof the actual speed pulses equals the frequency of the desired speedpulses.
 6. The control system of claim 5 wherein said wayside computingmeans includes a first, second, and third computing means having commoninputs and outputs, said first computing means calculating the desiredrailroad vehicle speed and outputting corresponding desired speedcontrol signals for transfer to the railroad vehicle, said secondcomputing means responsive to said first computing means to validate andto invalidate the outputted desired speed control signals, and saidthird computing means responsive to said second computer means forassuming the calculating and outputting functions of said firstcomputing means when said second computer means invalidates theoutputted desired speed control signals from the first computing means.7. The control system of claim 6 wherein said wayside computing meansinclude a data storage area having inputs and outputs to each of saidfirst, second and third computing means for providing data storagecommon to each of said computing means.